Hitherto, to attain high-speed printing using a wire dot printer, for example, a method was known (see, for example, Japanese Patent Laid-Open No. 60-73852) which comprised the steps of generating a secondary dot pattern from an original dot pattern showing fonts and the like by removing every other dot from the original dot pattern, and scanning a print head on the basis of the secondary dot pattern at a speed 2 times faster than usual to attain printing.
According to the method comprising the steps of converting the original dot pattern into the secondary dot pattern by removing every other dot out of the original dot pattern and performing printing on the basis of the secondary dot pattern, although the printing speed is doubled, the thus printed dot pattern is significantly distorted as compared with the original dot pattern, resulting in a poor quality of printing.